The invention is in the field of handling articles having bodies and members protruding therefrom, particularly such articles as electronic components having bodies and depending leads. During the manufacture of such electronic components, a particular pattern of one or more leads is known, and spacing tolerances between leads of a particular pattern are exact enough for insertion into a corresponding hole pattern of a circuit board. However, during attachment of the component body to the leads by soldering or the like, and during subsequent treating of the body after such lead attachment, such as encasing the body with a protective cover, irregularities can and do occur such that the body profile may become offset relative to the lead pattern in X, Y, .theta. or combinations thereof and result in a variation of the orientation and location of the lead pattern relative to the profile of the body. Such variation may occur between batches of components or from component to component in a particular batch. Such an offset between the body profile and the lead pattern presents problems in proper insertion of the leads into a corresponding pattern of circuit board holes during subsequent handling of the component.
With some types of components, such irregularities are overcome by engaging the component body with a vacuum tube and manipulating the vacuum tube to align the leads of the component with corresponding substrate holes according to an optics system or the like. Other types of components have bodies which do not lend themselves to handling by such a vacuum tube, so that, heretofore, they had to be manually oriented and inserted.
What is needed is a method and apparatus by which a great variety of components, particularly those having an offset between their lead pattern and their body profile and those having irregular body surfaces that do not lend themselves to vacuum pickup and handling, may be handled by their bodies such that automated compensation of the above-described displacement or offset of the body profile relative to the lead pattern is accomplished.
For purposes of disclosing and claiming this invention, a "nominal" pattern is one in which there is no relative offset of the body profile from a defined pattern; and an "actual" pattern is one in which there may or may not be such a relative offset. Hence, an offset of the "actual" lead pattern of a component from the "nominal" lead pattern which that component should have can be said to include the above-described irregularities. Further, the pattern need not be one of leads extending from the body. Rather, it may be a pattern of recesses or holes in the body which are to be mated with protruding members of another body. Additionally, a first body may have a mixed pattern of holes and leads for mating with a corresponding mixed pattern of holes and leads of a second body.
The above cross-referenced prior art is representative of the state-of-the-art alignment and orientation methods and devices presently available in automated or robotic component handling. As will be appreciated from the following disclosure, none of these references suggest or contemplate a solution to the problem of handling components in which the body and lead pattern are offset relative to each other and in which the components are handled by the bodies thereof such that proper orientation of the lead pattern relative to a corresponding hole pattern may be effected during a physical gripping of the component body.
Accordingly, it is an object of the instant invention to provide a method and apparatus for handling components having a body and leads depending therefrom in which the component may be gripped by the body for transport and in which a relative offset between a lead or hole pattern and the body profile may be compensated for during handling and mating of the pattern with a corresponding pattern in another body or substrate.
It is a further object of the invention to provide a method and apparatus for straightening leads of electronic components or the like during such compensating and prior to inserting the leads into their corresponding circuit board holes.
It is a further object of this invention to handle components which, because of irregular surface configurations, are not easily handled by vacuum pickup and transfer devices, while providing compensation for any relative offset between a lead pattern and body profile and providing the necessary accuracy for insertion of the leads into the holes of a corresponding hole pattern of a substrate.
In one embodiment of the invention, a component handling device is mountable upon known X, Y, Z-translatable robot arms or the like and provides "wrist" manipulation such that the device may assume various pick-up and insertion attitudes. The device has a gripper assembly which is "floatable" within a head assembly such that a component may be oriented according to the lead pattern for subsequent insertion into a corresponding hole pattern without regard to X, Y, and .theta. offsets of the lead pattern relative to the component body.